Lightroom Classic: Some keywords not in alphabetical order

Since I have updated to LR Classic, I have an issue with my keyword list. I have hierarchical keywords. Some on the top level are numbered and some of the top level have no child keywords. Since the update the keywords on the top level and the second level hierarchy are no longer in alphabetical order. Some keywords seem to be ordered correctly, but several others are not. The keywords which are not ordered alphabetically seem to get ordered by a change/creation date or so.

I do not use LR CC and have not done any keyword changes on my mobile devices.

Has anybody an idea, what I could do about it? Is there I setting, I have missed?

To locate the config.lua, Open Lightroom > Preferences > Presets Click on "Show Lightroom Presets Folder..."It should take you to folder ending with ... /Application Support/Adobe/Lightroom/

If config.lua is already present in Lightroom folder, just add, LibrarySort.useOldSort = truein the config.lua file. If the file is not present create a file named config.lua and add the same configuration there.